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.lUNrrsn Stratus PATENT riuca GEORGE Fl SCHXVEITZER, ()F LINCOLN,NEBRASKA.

PROCESS OF TANNBNG.

SPECIFTCATEQN forming part of Letters Patent No. 328,978, dated October27, 1885.

Serial No. 157,365. (No specimens.)

To (tZZ whom it may concern.-

Be it known that I, GEORGE F. SoHwEIrzER, a citizen of the UnitedStates, residing at Lincoln, in the county of Lancaster and State ofNebraska,haveinveuted certain new and useful Improvements in the Processof Tanning; and I do hereby declare the following to be a full, clear,and exact description of the invention, such as will enableothersskilled in the art to which it appertains to make and use the same.

Heretofore in tanning hides by the method called mineral process, thehides were soaked for a short time, commonly, in impure water, andthereafter all hides,without regard to their various qualities, werelimed for a certain equal and definite time, and were then placed in abrine of watcrand salt only, being thereafter removed and exposed forsome time to the smoke from a comparatively large quantity olsulphur,and subsequently tanned in a liquor containing salt, alum, and extractof hemlock-bark, with the occasional addition of japan-earth. Thismethod is crude and very unsatisfactory in its effect on the leather,both as to quality as well as appearance. By the old process of tanningwith bark,three months time at least was required to completely tan thehide, while by the newer mineral process the tanning can be accomplishedin from three to six days,and by my improvements leather is producedmuch tougher and more durable than has heretofore been secured, as wellas at a much less expense, than formerly.

The method I pursue and the compositions I use are as follows: The hidesare first soaked from one and a half to two days in pure fresh water tothoroughly cleanse them from blood and all extraneous matter, therebypreparing them to readily and quickly absorb the lime to be applied tothem. The hides are then limed, according to their sort or kind, forfrom six to ninevdays, and the hair removed. Ilarness-lcather, forinstance, does not require so much liming to make it strong and tough aswhip or net leather does. I then clean the hides and place them insaltwater in which five pounds of alum has been dissolved, in which Iallow the hides to remain at least two days. The alum in this brineaccomplishes a slight tanning effect on the hides, which I thinkdesirable, before they are submitted to the next process, which is toremove them from the brine and hang them up in a box,

where they are submitted to the fumes of sulphur. In this process caremust be exercised to not submit the hides to the sulphur-smoke too long.Hides intended for boot and shoe leather should remain in the smoke offour pounds of sulphur about twelve hours; for whip and net leather, insmoke of six pounds of sulphur for eighteen to twenty hours, while thickhides forsaddle and harness leather may remain in the fumes of eightpounds of sulphur for twenty-four hours. The hides are then placed in aliquor containing in solution Salt, alum, and extract of either hemlockor catechu, and sulphuric or muriatic acid.

For hides suitable for belt orharness leather, I use catechu instead ofhemlock, as being stronger, and sulphuric rather than muriatic acid,adding about onehalf a gallon of the sulphuric acid. The liquor shouldbe made weak at first and gradually made stronger, and for this qualityof hides should contain more alum than salt; but for hides to be madeinto fine bleached or aniline-colored leather, use alum and salt inequal quantities, and use sumac instead of hemlock or catechu. Thesulphuric acid should be put in a little atfirst, and graduallyincreased in amount until all is used.

Forhides suitable for boot and shoe and net leather, more salt than alumshould be put into the liquor, and extract of hemlock or chestnut usedinstead of catcchu, and instead of sulphuric acid use one-half gallon ofmuriatic acid.

Great care should be exercised to not make the liquor too strong atfirst; but all the material should be added to theliquor gradually.

The hides should be turned at least three times every day, andif all isproperly done the hides will be thoroughly tanned in from three to sixdays. Next remove the hides from the liquor,and scour them slightly,andhang them up in a warm room until wind'dried. Then take them down,moistening the parts (if any) that have become quite dry,and fold andpack them carefully, and, so far as possible, in such by hand with apreparation made of fivemanner that the drier parts will be upon the wet.or moist parts. Let them remain folded and packed one day. Afterwardstuff them with degras, tallow, and fish-oil mixed with some yellow wax.For .harness'leather use more t-allow than degras and fish-oil, and forwhip and net leather use more degras and fish-oil than tallow. Afterdrying I set out the hides twice and then finish up as usual.

In the foregoing description, the quantities of material named have beensuch amount as is used in the process for forty hides.

In the process for bleaching the hides for fine and aniline-coloredleather I usetwo baths,

which for twenty hides are made as follows: Five pounds of sugar of leadare put into sixteen gallons .of pure warm water, and one quart ofsulphuric acid isput into ten gallons of pure water, the two baths beingof course prepared in separate vessels. The hides are first drawnthrough the solution of sulphuric acid to cleanse them, and they arethen drawn three times through the solution of sugar of lead. Afterscouring slightly, I stuff them parts cod oil and one part of tallow.They are then dried in a warm room and afterward set out a first time,then dried againand set out a second time, and when dry I prime themwith red Brazil wood and apply the aniline color desired; but Ipreferably use yellow or red on this ground-priming.

What I claim as new, and desire to secure by Letters Patent, is-

1; The method of treating hides, consisting of, first,thoroughlycleansing them in pure fresh water; second, liming them toremove the hair; third, submerging them in a bath of water containingsalt and alum in solution; fourth, submitting them to the fumes ofsulphur; fifth, tanning them in a liquor having in solution salt,-alurn,sulphuric acid, and the extract of bark; sixth, bleaching in a bathcontaining sulphuric acid in solution, and, seventh, bleaching in a bathcontaining sugar of lead in solution, all in successive order, and

substantially as described.

2. In tanning hides, the following process: first, cleansing them bysoaking in pure water from one to two days; second, liming them from sixto nine days for removing the hair; third, submerging them in waterhaving salt and alum in solution for two or more days; fourth, exposingthemto the smoke of sulphur from twelve totwenty-four hours, and, fifth,curing them in a liquor containing in solution salt, alum, sulphuricacid, and the extract of a tanning-bark for from three to six days, theliquor to be made weak at first and gradually stronger, allsubstantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

GEORGE FL SCHWEITZEB.

Witnesses H. FRINOKE, M. FRINOKE.

